Spotlight on Faculty: Chandra Bhat

"Are you playing God?" people have asked Dr. Chandra Bhat. The people
who ask this question are referring to his work predicting the activity and
travel patterns of city inhabitants. This includes the prediction of if and
when individuals in a population get married, to whom they get married, if
and when marriages dissolve, where individuals choose to live, if and where
they work, whether and when they have children, and when they die. These decisions
determine the demographic composition and spatial dispersion of the population
in an urban region, which, in turn, says Dr. Bhat, helps predict the complete
daily activity-travel patterns of individuals in space and time.

The name of this line of work is Travel Demand Modeling. Dr. Bhat and his
graduate students have created a computer simulation program that predicts
the demographic, residential, and activity-travel patterns of individuals in
urban areas. This prediction system is used to examine the impact of alternative
traffic congestion alleviation and air quality improvement strategies (such
as traffic congestion pricing, fixed and time-varying tolls, work rescheduling,
light rail and commuter rail service, parking policies, and telecommuting),
and to plan for the aftermath of extreme events (such as terrorist attacks,
earthquakes, and hurricanes).

Using the information he gathers, Dr. Bhat works to find ways to make transportation
balanced—to have convenient grocery stores, day-care centers, and other
indispensable resources close to where people live and work, and close to such
transportation hubs as commuter rail stations. This requires solid land use
planning as well as transportation planning. He says: "We do some of the
research because people can actually use it—and we also do research because
we love it."

One of the wonderful things about this research is the extent to which it
is, in a way, intuitive. How many times have we looked at a city of sprawl
and criticized it for its loneliness? How will the city’s inhabitants
connect and identify with each other? Where can people gather? Where can people
walk and bicycle? Through scientific and urban planning methods, Dr. Bhat studies
demographics and the built environment (for example, the layout of a city and
the nature of the transportation system) impact activity and travel patterns.

Many European cities, as well as the core of San Francisco, have compact geographic
footprints, Dr. Bhat says. These cities depend on their public transportation
systems. On the other hand, many of the large cities in the United States
have spread horizontally, which makes it difficult to pinpoint places where
public transportation would be useful for large groups of people. In
turn, this requires inhabitants to get from place to place by driving alone.

Dr. Bhat developed an interest in these ideas while he was still in graduate
school, which he finished in 1988. What drew him was the interdisciplinary
nature of Travel Demand Modeling: it’s combining of mathematics, econometrics,
engineering, urban planning, and social science. Because of the wide social
relevance of this work, Dr. Bhat notes, "there is no dearth of people
knocking on our students’ doors and offering them jobs." His former
students go on to study travel patterns in cities all over the world in transportation
consulting firms as well as in universities.

As for his own transportation habits, Dr. Bhat says that he tries to be physically
active and walks or bicycles when he can to access activities. "Hopefully," he
says, "it will rub off on my own children."